Linked Life Data

8951684

Source:http://linkedlifedata.com/resource/pubmed/id/8951684

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1997-2-20
pubmed:abstractText
The aim of the present study was to compare, in healthy human volunteers (male and female), the corneal contact time of various formulations, each containing one viscosity enhancer from the following list: a phase-transition system (gellan gum, Gelrite), a heteropolysaccharide (xanthan gum) and currently used polymers hydroxyethylcellulose, hydroxypropylmethylcellulose, or poly(vinyl alcohol). These different solutions were compared to a reference solution containing no viscosity enhancers. The corneal contact time of the formulations was evaluated over more than 20 minutes by gamma scintigraphy using Technetium-99m (Tc-99m DTPA) as a radioactive label. An eyedrop containing pilocarpine salts (25 microliters) was instilled in one eye only. Each volunteer received 4 formulations, the interval between the instillations being one week. The protocol has been approved by the relevant institutional human experimentation committee. One minute after instillation, only 23% of the reference solution remained on the ocular surface, whereas the novel formulations maintained, respectively, 77% (xanthan gum) or 82% (Gelrite) of the tracer on the ocular surface. Twenty-one min after instillation, 12% (reference solution), 25% (xanthan gum solution), and 39% (gelrite solution) of the tracer remained on the ocular surface. The results confirm that an increase in viscosity of the formulation (xanthan) delays the clearance of the instilled solution by the tear flow. The effect of the gelation mechanism is superior, especially at the later time points. In this respect, xanthan gum and, particularly, Gelrite are suitable vehicles for ophthalmic drugs.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1080-7683
pubmed:author
pubmed:issnType
Print
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
481-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Gamma scintigraphic comparison of eyedrops containing pilocarpine in healthy volunteers.
pubmed:affiliation
School of Pharmacy, University of Geneva, Switzerland.
pubmed:publicationType
Journal Article, Comparative Study